The present invention pertains to prefabricated concrete building panels having one surface coated with an adhered insulating material, such as styrofoam, permanently bonded to it and which is applied into a form before concrete is poured into it. The form is sized to predetermined dimensions conforming to the size and thickness of the panels to be cast and comprises four side walls which are preferably of steel; and a flat base or floor spans the upright side walls; and upon this floor the styrofoam inserts, generally downwardly opening and box-like in configuration, are placed. The styrofoam inserts are separated by strips of wood such as furring strips which also are placed about the entire inside perimeter of the form to provide a separation between the form and the styrofoam inserts.
It is therefore a principal object of this invention to provide relatively lightweight prefabricated concrete building panels with cast in insulation permanently bonded to the concrete and wood fastening strips for attaching paneling, sheetrock, etc. thereto.